Electromagnetic relay



Feb. 25, 1958 Filed Dec. 30, 1953 A. J. MoNTcHAussE Er AL ELECTROMAGNETIC RELAY 2 Sheets-Sheet l Inventor A. J. MONTCHAUSSE' D DAUTRY Attorney 2,824,923 ELECTROMAGNETIC RELAY Andr Jean Montchauss, Paris, and Daniel Dautry, Clamart, France, assignors to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application December 30, 1953, Serial No. 401,287 Claims priority, application France December 31, 1952 7 Claims. (Cl. 200-104) The present invention relates to an improvement in electromagnetic relays of the type described in the copending patent application of D. Dautry, filed December 13, 1951, and bearing Serial No. 261,538. it also deals with certain improvements intended to standardize the various component parts of electromagnetic relay members and consequently reduce the manufacturing and assembly cost.

In the said copending patent application, the fixed contact blades are carried by a guide bar, the movable contact blades being interlocked with another guide bar placed under the control of the armature lever. The contact blades are set freely, but without play, in notches provided on the guide bars.

One of the features of this invention lies in that the profile and the spacing of the notches on the two guide bars are identical and the two bars are staggered with respect to each other a distance equal to the spacing be-- tween movable and fixed contact blades.

Another feature of this invention lies in that staggering of the bars is achieved by having the fixed guide bar resting with its shoulder on the edge of a recess provided on the base plate of the contact blade series, the shank of said guide bar resting in this recess, and in that the shank of the movable guide bar rests on the opposite edge of said recess, the length of the movable guide bars shank defining the displacement between the notches of the two guide bars, the other end of each of these bars carrying a lug resting in the corresponding opening of a spring blade, each of these bars being held in position by said base plate, said spring blades and the contact blades themselves and all displacement of the bars with respect to the spring blades being made impossible.

Another feature of this invention lies in providing an interchangeable series of the movable and fixed contact blades, the insulating plates and a base plate.

Another feature of this invention lies in providing a plate of nonmagnetic material held fast between the base plate of the contact blades and the yoke and having a hole to accommodate the projection of said base, said plate allowing the base to rest with its two ends on the yoke and eitectively acting as a stop for the armature lever, thus preventing any adhesion between said lever and the yoke due to the residual magnetic flux.

Another feature of this invention lies in inserting between the movable and fixed guide bars and the base plate of the contact blades a washer with a stamped projection, said projection resting in a recess of the base plate of the contact blades and the position of the two guide bars with respect to the clearance of the Washer being the same as the position they would occupy with respect to the recess of the base in the absence of the washer, the available space between the armature lever and the shoulder of the movable bar, equal to the thickness of the washer, being used for a make-first contact, the armature lever acting first on said contact and then on the movable bar by means of said contact.

nited States Patent 2,824,923 Ce Patented Feb. 25, 1958 Another feature of this invention lies in providing a member in the form of a bolt, attached to the yoke and fitting into a slot provided on the armature, thus preventing any displacement of the armature either along its axis or in the direction of movement of the guide bars.

Various other features will become apparent from the following description, given as a nonlimitative example with reference to the attached drawing, in which:

Fig. l is a side view of the relay assembly;

Fig. 2 is a top view of the relay of Fig. 1, showing only one of the series of contact blades;

Fig. 3 shows a variant of Fig. 1 provided with a makefirst contact;

Fig. 4 shows a variant of Fig. 2 provided with a twoever armature with the two series of contact blades not shown;

Fig. 5 is a side view of the base part of the contact blades;

Fig. 6 is a top view of the base part of Fig. 5;

Fig. 7 is a top view of the stop plate for the armature lever;

Fig. 8 is a large-scale partial sectional view along line aa of Fig. 1 showing two guide bars, one movable and the other fixed, in their proper position on the relay;

Fig. 9 is a large-scale partial sectional view along line b-b of Fig. 3 showing two guide bars, one fixed and one movable, where a make-first contact has been provided.

Fig. 10 is a schematic view showing one of the contact combinations obtainable with the guide bars used.

Referring now to Figs. 1 and 2, a detailed description of the relay of the invention will now be given, discussing first the case of a relay having two assemblies capable of acting independently of each other. Each of these assemblies comprises a core 1 and a fiat-wound coil consisting of one or more windings 2, end flanges 3 and 4, and connection lugs 5, 6, 7 for connecting said winding or Windingsto external electrical circuits. Core 1 is fastened by a screw 8 to L-shaped yoke 11. The two relay assemblies are identical in design and are mounted on the same yoke. Armature 12, pivotally mounted over one of the edges of the yoke, is held in position by a bar 13, said bar being fastened to the yoke by means of a screw 14, any sidewise movement being prevented by the projection 15' which protrudes from the yoke and is adapted to engage the slot created by fork-shaped part 16, in an end of bar 13. The armature can thus pivot freely over the edge of the yoke, any other movement being made impossible by members 17, 18, 21 and bar lug 22.

The set of contact blades 24 to 32 forms an interchangeable assembly mounted on a base part 23. This assembly comprises insulating plates 35 and 36, contact blades 24 to 32 being separated by insulating plates 37 of equal thickness, plates 38, two spring blades 71, 63 and a holding plate 43. The various members forming the assembly are assembled and then fastened to base part 23 with screws 44 and 45. The set consisting of the contact blade assembly and base part 23 is fastened to yoke 11 by screw 46. Fig. 6 shows the profile of base part 23 including the two threaded holes 47 and 43 used for the assembling screws 44, 45 and hole 51 with a slightly larger diameter to clear screw as. In Fig. 2 one of the contact blade assemblies has been removed to show the threaded hole 39 into which screw 46 is fastened and the two holes of slightly larger diameter 49 and 50 provided to clear the ends of screws 44 and 45. Any rotary movement of base plate 23 is prevented by projection 52 on the bottomside of plate 23 itself and resting in a hole 40 provided in the yoke. This hole 40 is elongated to oval shape, as shown in Fig. 2, so that the dimensions between holes 39 and 40 and hole 51 and projection 52 do not have to match exactly.

A thin plate 53 of nonmagnetic metal (Figs. 1 and 7) i is provided to perform a double function: it acts as a stop for lever 54 of armature 12, thus preventing said lever from pressing directly against the yoke when the relay is in its deenergized position thereby preventing any residual magnetic adherence between the lever and the yoke; in addition, it allows base plate 23, which need not be exactly flat, to rest effectively with one of its ends on the yoke and its other end on plate 53. Hole 55 of plate 53 is provided to admit projection 52, said plate being thus guided and held between yoke 11 and base part 23. A shoulder 56 has been provided on base part 23 to allow clearance of the lever end 54 of the armature so that it may contact plate 53.

The contact blades are set freely but without play in the guide bar notches according to the method indicated in the said copending application. The bar 57 (Fig. 8) carrying the fixed contact blades has a shoulder portion 53 which rests on base part 23, under pressure of spring 71 (Fig. 1) against its opposite end 64, its shank 61 coming to rest in the recess 62 of the base part located on the opposite side of base part 23 behind projection 52. In practice, projection 52 and recess 62 are obtained by protrusion. The other end 64 of the fixed bar 57 rests in a complementary-shaped hole provided in spring 71. The bar 57 is thus kept in position by base part 23, by spring 71 and by the fixed contact blades themselves. The bar 65 carrying the movable contact blades is identical with the one carrying the fixed contacts but its arrangement is slightly different. When the relay is in deenergized position, shank 66 of said bar rests on base part 23, armature lever 54 abutting against bar shoulder 67. The other end 68 of movable bar 65 rests in a complementary hole provided on drawback spring 63, in the same fashion the fixed bar 57 rests in spring 71.

Notches 72 of fixed bar 57 are equidistant, as are notches 73 of movable bar 65. The spacing of the notches is the same as the constant spacing of the superposed fixed and movable blades, this arrangement allowing the use of insulating plates 37 of a thickness equal to the notch spacing to insulate the various contact blades. By proper arrangement of the fixed and the movable blades in the corresponding bar notches and by providing the proper number of notches, it is possible to obtain all desired contact combinations. In the embodiment described it was assumed that each bar had nine notches. The positions of the fixed and movable contact blades have been represented in Fig. 8 by dots. The embodied combination as shown schematically in Fig. comprises a back contact 24, transfer contact 25, two front contacts 26, 27, 23, 29 and a back contact 31, 32, the contact blades are seen sideways and notches 72 and 73 are represented by heavy lines. The position displacement or staggering between the slots of the fixed and the movable bars is defined by the length of their shank, for one or" the bars 65 rests on part 23 with its shank 66 and the other 57 with its shoulder 58; this displacement has been so chosen to assure proper pressure between the back contacts.

It is to be noted that because of the presence'of stop plate 53, base part 23 undergoes a slight elastic distortion, but this is of no concern since it does not afiect the relative position of the two guide bars and consequentlythat of the springs.

it is also to be noted that certain notches located at both ends of the bars can remain unused; then other insulating plates such as 35, 36 or 38 must be provided as shims to assure the springs actually located in the assembly a position adjacent to their theoretically correct notch position in their associated bar 57 or 65 as the case may be. I

In the deenergized position the movable parts of the relay are in the position shown in Fig. l of the drawing. When the circuit of coil 2 is completed, armature 12 is attracted by core 1 and rocks around the edge of yoke 11;

lever 54 of said armature leaves stop plate 53 and shifts movable bar to the left; movable contact blades 25 and 32 leave corresponding fixed contact blades 24 and 31, and the movable contact blades 25, 27 and 29 come into contact with the corresponding fixed contact blades 26, 28 and 30. When'the circuit of coil 2 is broken, armature 12 is no longer attracted by core 1, movable bar 65 is urged by drawback spring 63 to return to its initial position, restoring the various movable blades to the position shown in the drawing and at the same time so ing on armature lever 54, which comes to rest against plate 53.

The ends of the blades carrying the contacts being held in position 'by the insulating bars 57 and 65, the only adjustment in position to be made is that of the endof the armature lever 54 to insure the correct distance between the armature 12 and the end of the coil core; this adjustment is made by twisting the lever 54 with a properly shaped camber. In addition, adjustment of the elastic tension of drawback spring 63 belonging to the movable guide bar can be made by slackening this spring, which may have been given a higher tension than needed.

The above-described relay contacts open and close at the same instant, but it is possible, by using the arrangements shown in Figs. 3 and 9, to obtain a make-first contact, that is to say, one that closes before any of the other contacts has changed position. In this case, a washer 74 with a stamped projection 75 is placed between base plate 23 on the one hand and the fixed and movable guide bars 57 and 65 on the other. The stamped projection 75 is adapted to seat in the recess 62 provided on base plate 23. Shoulder 58 of the fixed bar 57 rests on one edge of washer 74, while shank 61 of said bar rests in the hole 75a of the washer. Shank 66 of movable bar 65 rests on the opposite edge of the washer. These arrangements provide a spacing equal to the thickness of washer 74 between shoulder 67 of the movable guide bar and armature lever 54 which space is used for the accommodation of make-first contact 76, 77. This contact consists of two blades 76 and 77 assembled in the same set as the other contact blades. An insulating plate 78 with the same profile as blade 76 prevents any electrical contact between said blade and the armature lever 54. A further insulating plate (not shown) may be provided if required to allow proper spacing between blade 76 and base plate 23 for the camber used to regulate the tension of the two contact blades 76 and 77.

When the armature is attracted by the core, armature lever 54 acts first on blade '76, the contacts on said blade pressing against those on blade 77. The make-first contact is thus closed before any of the other relay contacts have changed position. The armature lever then acts, by means of contact blades 76 and '77, on movable bar 65 and the operation continues according to the method just described.

When the relay is required to control a number of contacts greater than the capacity of a contact blade assembly, a second contact blade assembly is added to yoke 11 the second assembly parallel to the first. In this embodiment an enlarged armature 81 with two le ers 54 and 54' (Fig. 4) is used each operating a movable bar guide 65. The blade assemblies are not shown in Fig. 4, in order to simplify the drawing. The armature is held in position on the edge of the yoke by the same bar 13 described above; the hole and the projection used to fasten this bar to the yoke are the same as those provided on the right-hand member in Fig. 2, the bar simply being turned around so that stud 22 keeps armature 8i centered just as the armatures in Fig. 2 were kept centered.

Relays of three or more contact blade assemblies can also be provided by using an armature with one operating lever per assembly and a yoke of proper dimensions. To obtain the magnetic flux necessary for operating these various contact blade sets, one or more coils each having a core of proper section can be used, said core being embodied for example by a stretched disc.

A number of relays, each comprising one or more contact blade assemblies, can be mounted on the same yoke With dimensions corresponding with the number of relays.

The relays described above offer certain advantages. The yoke is simple in shape. The number of different parts needed is small; the fixed and movable guide bars are interchangeable; besides the make-first contact blades, only two contact blade blanks need be provided. Depending on whether it is a fixed or a movable blade and depending on the position of the connecting shank, the first blank is used for the fixed blades of odd rank and the movable blades of even rank, the second blank serving for the fixed blades of even rank and the movable blades of odd rank. The insulating plates separating the various blades are the same in all cases; the same bar can be used for holding armatures having one, two or three levers or more. The various holes provided on the yoke, threaded or not, are also the same for a given number of contact blade assemblies, whether these assemblies are operated by individual armatures or by an armature common to a number of levers. All these arrangements facilitate manufacture and allow reducing costs.

It is quite obvious that the preceding descriptions have been given only as a nonlimitative example and that it would be possible, among other variants, to provide bars with a greater number of notches, provide other contact combinations, and modify the profile of the contact blades or that of the springs, all without departing from the scope of the invention.

What is claimed is:

1. A multi-contact relay, comprising an electromagnet and a cooperating armature, a mounting yoke attached to said electromagnet, a pile-up of cooperating fixed and movable contact blades, a pair of identical guide bars of insulating material, one of said bars under control of said armature, each of said bars having a series of spaced notches along an edge thereof, said bars being oppositely positioned so that the notched edges thereof are mutually adjacent the notches in said bars adapted to accommodate said fixed and movable contacts, respectively, means for maintaining an end of each of said bars a different distance from said yoke in one condition of operation of said relay, whereby the notches of each bar are staggered with respect to the corresponding notches of the other, the staggered distance being equal to the difference in the distance of the ends of each of said bars from said yoke, said means comprising a shoulder cut into a first end of each of said bars, support means in termediate said yoke and said bars, said support means adapted to abut against the shoulder of a first of said bars and against the end of the second of said bars, said armature adapted to cooperate with the shoulder of said second bar to urge same out of abutment with said support means.

2. A multi-contact relay as claimed in claim 1, Wherein said means for maintaining said bars a different distance from said yoke comprises a pair of tension blades, each of said blades abutting against a second end of each of said bars and exerting a force thereagainst in the direction of said yoke.

3. A multi-contact relay as claimed in claim 1, further comprising a lever having one end attached to said armature and the other end adapted to abut against the shoulder of the second of said bars.

4. A multi-contact relay as claimed in claim 3, further comprising a pair of cooperating contacts, said contacts interposed between the shoulder of the second of said bars and said lever, said lever adapted to urge said contact pair into contact prior to the movement of said second bar upon energization of said electromagnet.

5. A rnulti-contact relay as claimed in claim 3, wherein said tension blades are included in said contact blade pile-up.

6. A multicontact relay as claimed in claim 3, further comprising a shoulder cut into the other end of each of said bars, each of said last mentioned shoulders cooperating with a different one of said tension blades.

7. A multi-contact relay comprising an electromagnet, a mounting yoke attached to said electromagnet, an armature pivotally mounted over an edge of said yoke and cooperating with said electromagnet, a pile-up of tensioning means, fixed and movable contact blades insulatedly mounted from said yoke and from each other, a pair of identical guide bars of insulating material, each having a series of spaced notches along an edge thereof, said bars being oppositely positioned so that the notched edges thereof are mutually adjacent a portion of said fixed contact blades adapted to be inserted in predetermined of the notches in a first one of said guide bars and a portion of said movable contact blades adapted to be inserted in predetermined of the notches in said second guide bar, each of said guide bars having a pair of shoulders cut in opposite ends thereof, the shoulders in a first end of said guide bars abutting against said tensioning means, support means intermediate said pile up and said yoke for maintaining said guide bars a predetermined distance from said yoke, said support means adapted to abut against the shoulder in the other end of said first guide bar and against the other end of said second guide bar, the notches of each of said guide bars adapted to be staggered with respect to and facing the corresponding notches of the other bar, the depth of the shoulders in the second ends of said guide bars equal to the distance of the staggering of said notches, lever means coupled to said armature adapted to abut against the shoulder in the other end of said second guide bar for moving said bar against the tension of said tensioning means upon energization of said electromagnet.

References Cited in the file of this patent UNITED STATES PATENTS 2,077,091 Brander 2. Apr. 13, 1937 2,235,861 Wood Mar. 25, 1941 2,282,687 Vigren et al May 12, 1942 2,401,213 Wood May 28, 1946 2,473,982 Wood June 21, 1949 2,602,867 Vincent July 8, 1952 2,612,367 Blomqvist Sept. 30, 1952 2,686,850 Earle Aug. 17, 1954 FOREIGN PATENTS 620,972 Great Britain Apr. 1, 1949 

